Method of producing condensation products.



ran s'rarns PATENT caries.

HOW.ARD W. MATHESON, WILMINGTON, DELAWARE. ASSIGNOR TO E. I. DU PONT DE NEMOURS POWDER COMPANY, OFWILMINGTON, DELAWARE, A CORPORATION OF NEW JERSEY. I

METHOD or PRODUCING CONDENSATION PRODUCTS.

No Drawing.

To all '10]! am. it may con cern Be it known that I, Howann W. I\L\THESON, of Wilmington, in the county of New Castle, and in the State of Delaware, have invented a certain new and useful Improvement in Methods of Producing Condensation Products. and do hereby declare that the following is afull, clear, and exact description thereof.

My. invention relates to aprocess of producing condensation products of organic compounds of different kinds. and is applicable to the production of condensation products of many different varieties within the field of organic compounds.

My invention is particularly applicable, however, to the production of condensation products of aldehydes and ketones, and especially to the production of acetaldol from acetaldehyde by the condensation of two molecules of acetaldehyde to produce one molecule of acetaldol, in accordance with the following equation CH,C1IO+CH,CHO:

, CH,-CHOH--OH,CHO.

Prior to the time of my invention, such condensation products have been usually obtained by the use of different agents. preferably metallic salts such as the carbonates, cyanids or sulfites. The use of these substances is. however, attended with marked disadvantages owing to the fact that their action is very slow and the amount of condensation product obtained correspondingly small, and further, that their isolation from aqueous solutions is tedious and expensive. The metallic hydroxids could not be used for this purpose as their addition to acetaldehyde causes the formation of yellow resinous products, known as acetaldehyde resins. (See the Leizmbuch cler Organise/ten Ohemie of Meyer-Jacobson.) It has also been proposed. in an application of Harold Hibbert.

to carry out the condensation by the use of solid metallic hydroxids in other solvents than water.

I have discovered a process of producing condensation products. particularly the production of acetaldol from acetaldehyde, in which a metallic compound, preferably a. metallic hydroxid. may be used, by which much better results can be obtained than in any of the processes previously used. By

Specification of Letters Patent.

Patented Aug. 24, 1915.

Application filed AuguSt19, 1912. Serial No. 715.738.

means of my invention. I am enabled to obtain acetaldol by the use of a metallic hydroxid without any tendency to produce the resinous products ordinarily obtained by the action of metallic hydroxids. I have discovered that if the condensing agent is dissolved in a nonaqucous solvent containing little or no water, for example. sodium or potassium hydroxid dissolved in 98'; ethyl alcohol, and the solution added to the acctaldehyde or other substance to be condensed, an improved yield of the acctaldol is obtained without relyiing on the use of any other solvent.

By the expressionnon-aqueous sol vents, I mean a solvent other than water but which may nevertheless contain some water.

lVhile my invention is capable of application to many condensation reactions. as one illustrative embodiment thereof I may proceed as follows: Two hundred gra ms of freshly distilled acetaldehydc boiling point 21 to 28 are cooled to a temperature substantially not below 20 C. and substantially not above +20 0.. and then a 10% solution of caustic potash dissolved in ethyl alcohol slowly added. the contents being vigorously shaken. The product is then kept betwccn substantially +5 and +10 C. for several hours, preferably not more than twenty-four. After neutralizing the free alkali present and filtering from the potassimn or sodium salt. the product consists of pure acetaldol. mixed only with a slight amount of acetaldehyde. from which it can be readily freed, if desired, by a subsequent distillation under reduced pressure. While in the above example I have used ethyl alcohol and caustic potash, other alkalis or alkaline salts, for example, sodium ethylate aldehyde a non-aqueous solution of an alkali, the reagents mentioned being cooled to a temperature below 10 C.

2. The process which comprises forming an aldol by bringing into contact with an aldehyde an alcoholic solution of an alkali, the reagents nlentioned being cooled to a temperature below 10 C.

The process which comprises forming an aldol by bringing into contact with an aldehyde, a non-aqueous solution of caust1c.

6. The process which comprises forming,

an aldol by bringing into contact with an aldehyde, an alcoholic solutlon of an alkali,

keeping the mixture cooled to a temperaturebelow 10 C., neutralizing the free alkali, and separating the aldol from the remaining substances.

7. The process which comprises forming an aldol by bringing into contact with an aldehyde, a non-aqueous solution of caustic potash, keeping the mixture cooled to a temperature below 10 C., neutralizing the free alkali, and separatmg the aldol from the remaining substances.

8. The process which comprises forming 40 an aldol bybrlnging into contact with an aldehyde, an alcoholic solution of caustic potash, keeping the mixture cooled to a temperature below 10 0., neutralizmg the free alkali, and separating the aldol from the remaining substances.

9. The process which comprises forming an aldol by bringing into contact with an aldehyde, a non-aqueous solution of an alkaline substance, the reagents mentioned being cooled to a temperature below 10 C.

10. The process which comprises forming an aldol by bringing into contact with an aldehyde, an alcoholic solution of an alkaline substance, the reagents mentioned being cooled to a temperature below 10 C.

11. The process which comprises forming an aldol by bringing into contact with an aldehyde, :1 non-aqueous solution of a caustic alkali, the reagents mentioned being cooled to a temperature below 10 C. 1

12. -.The process which comprises forming I I an aldol by bringing into contact with an aldehyde, an alcoholic solution of a caustic alkali, the reagents mentioned being cooled to a temperature below 10 C.

In testimony that I claim the foregoing I have hereunto set my hand.

HOWARD W. MATHESON. Witnesses:

C. R. MUDGE, A. M. GoRMAN. 

